28nm HKMG 1F-1R2 Multilevel Memory for Inference Engine Application

This article reports 28 nm high-k-metal-gate (HKMG) based 3bits/cell memory with one ferroelectric (Fe) field effect transistor (FeFET) and one reconfigurable resistor (R
²
). R
²
, connected with the select line (SL) and the drain terminal of the FeFET, can be reconfigured via the SL terminal. R2 can be implemented by using a standard metal-oxide-semiconductor field effect transistor (MOSFET) as voltage controlled resistor or any two terminal programmable resistors. The detailed discussion about R2 is beyond the scope of this paper. The 1F-1R
²
cells demonstrate current-based 3bits/cell operation over a 300mm wafer and stable retention characteristics at 85°C for all eight current levels.